[Separation and study of two serum factors involved in the inhibition of the maternal cytotoxic reaction against embryonic cells in pregnant salamandra (author's transl)].

In vitro experiments in pregnant salamanders show a maternal specific cytotoxic reaction against larvae cells and an inhibition of this reaction by maternal serum. The last one is double: non-specific inhibition of maternal cellular reaction and specific protection of embryonic cells. Two fractions have been isolated from maternal serum, with biological properties in cell cultures: the first one is a protein (migrating as alpha2-macroglobulin does) which is implied in non-specific immunosuppression of maternal cells; the second fraction contains an IgM and specifically protects embryonic cells against maternal cytotoxicity.